A junior star in Kingston, n 1912 he moved on to the Toronto Blueshirts of the National Hockey Association, forerunner of the NHL. In 1913-14 he captained Toronto to a Stanley Cup championship. He ranked in the top ten in goals for the second season in a row. He also displayed his playmaking ability by finishing 2nd in assists that season.
Upon the outbreak of the First World War in 1914, Davidson volunteered with the Canadian Armed Forces. He was the first professional hockey player to do so. He was killed in action while fighting in Belgium in 1915. Hailed as a hero by his peers, Davidson was said to have been killed after refusing to retreat during a battle. Another account of his death suggested that he was shot in the back and killed while attempting to carry an injured soldier to safety. His life is commemorated on the Canadian National Vimy Memorial.
Davidson was posthumously inducted into the Hockey Hall of Fame in 1950. Perhaps his tragic demise played a role in such posthumous awards. In 1925 MacLean's magazine named Davidson to their All Time Hockey Team.